'a is known as a phantom type. The implementation is
actually monomorphic (the different element types are distinguished
by a homogeneous variable, such as their textual representation)
and the type variable `a is just used by the type checker.

NB: It might be possible to use polymorphic variants directly, without
phantom types, but the implementation is likely to be more involved.

This attribute offers advisory information about the element for
which it is set.

Values of the title attribute may be rendered by user agents in a
variety of ways. For instance, visual browsers frequently display
the title as a tool tip (a short message that appears when the
pointing device pauses over an object). Audio user agents may
speak the title information in a similar context.

The title attribute has an additional role when used with the link
element to designate an external style sheet. Please consult the
section on links and style sheets for details.

This attribute assigns an access key to an element. An access key
is a single character from the document character
set. NB: authors should consider the input method of the
expected reader when specifying an accesskey.

This attribute gives an advisory hint as to the content type
of the content available at the link target address. It
allows user agents to opt to use a fallback mechanism rather
than fetch the content if they are advised that they will
get content in a content type they do not support.Authors
who use this attribute take responsibility to manage the
risk that it may become inconsistent with the content
available at the link target address.

This attribute specifies the visible width in average
character widths. Users should be able to enter longer lines
than this, so user agents should provide some means to
scroll through the contents of the control when the contents
extend beyond the visible area. User agents may wrap visible
text lines to keep long lines visible without the need for
scrolling.

This attribute specifies the number of visible text
lines. Users should be able to enter more lines than this,
so user agents should provide some means to scroll through
the contents of the control when the contents extend beyond
the visible area.